class Query(object):
    """

    """
    def __init__(self, tables=None, where_clause=None, where_clause_params=None, joins=None, extras=None):
        pass

    def _get_table_aliases(self):
        pass

    def _get_alias_mapping(self):
        pass

    def add_join(self, connection, implicit=True, outer=False, extra=None, extra_params=[]):
        pass

    def get_sql(self):
        pass

    def __str__(self):
        pass
